1. Field of the Invention
The present invention is generally directed to an angular position sensor and more particularly pertains to a sensor that is capable of extremely accurate angular position determinations in very hostile environments.
2. Description of the Related Art
There are many applications in which the accurate determination of the angular position of one component relative to another is critical. Moreover, accurate determination of angular position allows for the accurate calculation of angular speed and acceleration which is vital, for example, for the effective operation of high performance anti-lock or anti-skid braking systems. The components of braking systems may be subjected to fairly extreme conditions, including high temperatures, vibration and shock loads, as well as water and dirt contamination. Such conditions are further amplified in aircraft applications.
Certain previously known aircraft anti-skid systems have relied on a driveshaft to distance a relatively fragile sensor from the harsh conditions that exist immediately adjacent the brakes and wheel. While such a configuration allows for the use of a reliable and accurate inducer to generate the required wheel speed data, the weight, bulk and complexity of such a system is disadvantageous. A system relying on low frequency RF signals to generate wheel position and speed data has been employed. The use of Hall sensors has also previously been proposed, but the configurations that had been considered rendered the sensors particularly susceptible to heat damage and required an inordinate number of magnets and sensors in order to achieve the desired accuracy.
An angular position sensor is needed that this capable of generating extremely accurate position data for use in for example angular speed and/or acceleration calculations. Moreover, the sensor needs to be capable of reliably functioning in extremely hostile environments.